1. Field of the Invention
The invention relates to a vacuum cleaner suction pipe with at least one inner pipe, at least one outer pipe, and at least one locking device, the inner pipe having a toothed strip, the locking device being attached to the outer pipe, the locking device being movable by manual actuation by a user from a locking position into a release position, the locking device having a toothed rack, and the rack being kept engaged to the toothed strip of the inner pipe in the locking position, as a result of which the position of the inner pipe is fixed relative to the outer pipe.
2. Description of Related Art
Vacuum cleaner suction pipes are known in the prior art in a host of configurations. Vacuum cleaner suction pipes establish the connection between the suction hose of a vacuum cleaner and the suction tool, for example, a floor nozzle. In order to match the length of the vacuum cleaner suction pipe to the individual requirements of a user, vacuum cleaner suction pipes can be changed with respect to their length by, for example, a inner pipe being telescopically guided in an outer pipe. The length of the vacuum cleaner suction pipe is set incrementally by relative displacement of the inner pipe relative to the outer pipe. The shortest distance of a change in length is determined, for example, by the minimum distance of a catch depression which is used to lock the pipes relative to one another.
European Patent Application EP 0 937 435 A2 discloses a vacuum cleaner suction pipe with an inner pipe and an outer pipe, the inner pipe having embossed depressions which interact with a locking mechanism which is attached to the outer pipe. Here, the locking mechanism has elastic catch hooks which in the locking position engage the embossed depressions in the inner pipe and thus fix the position of the inner pipe relative to the outer pipe. By actuating the locking mechanism, the catch hook is enabled to move aside so that it moves elastically aside out of the depressions in the inner pipe opposite the spring force applied by its holder, as a result of which resetting the position of the inner pipe relative to the outer pipe by the user is enabled. As soon as the next catch depression is reached, the spring force leads to the catch hook being pressed into it.
The vacuum cleaner suction pipes known from the prior art have the disadvantage that a relatively temporary stabilization of the set position between the inner pipe and outer pipe can only be accomplished with an additional spring force which is acting on the spring elements so that, even with the locking mechanism released by the user, a spring force must always be overcome in order to move the inner pipe relative to the outer pipe; this means additional effort for the user. Furthermore, the known vacuum cleaner suction pipes have the disadvantage that the distance between the locking positions is relative large, as a result of which only rough adjustment is possible.